A technology for transmitting a signal by performing alternating current (AC) coupling is known. There is a technique as an AC coupling technique that incorporates a condenser or capacitor in a wiring board on which an electronic component such as a semiconductor device is mounted. For example of the technique, there is known a wiring board on which a condenser is formed by signal-line pads that oppose each other with a certain insulating layer being interposed therebetween. The signal lines are provided on upper and lower surfaces of the certain insulating layer.
Japanese Laid-open Patent Publication No. 2009-200108 is an example of a related art.